Hammer mill



Jan. 19, 1937. A. c. LINDGREN ET AL 2,063,383

HAMMER MILL Filed Feb. 25, 1953 4 Sheets-Sheet 1 4 Sheets- Sheet 2 A. C. LINDGREN ET AL HAMMER MILL 1 Filed Feb. 23, 1953 Jan. 19, 1 937.

NW mw Jan. 19, 1937. A. c. LINDGREN ET AL 2,068,383-

HAMMER MILL Filed Feb. 23, 1933 4 Sheets-Sheet 3 Jan. 19,1937. A. c. LINDGREN ET AL 2,068,333

v HAMMER MILL 4 Sheets-Sheet 4 I Filed Feb. 23, 1935 Patented Jan. 19, 1937 PATENT OFFICE HAMIHER. MILL Alexus C. Lindgren, Chicago, and Clemma R.

Raney, Riverside, 11]., assignors to International Harvester New Jersey Company, a corporation of Application February 23, 1933, Serial No. 657,982

1 Claim.

The invention relates to hammer type feed grinding mills of the kind embodying a cylindrical drum provided with a feed opening in one side face and a discharge or exhaust opening for the reduced material adjacent the periphery of the drum.

The primary object of the invention is to locate the feed opening in such a manner with respect to the exhaust or discharge opening that the rotor upon which the reducing means is mounted must carry the material worked upon substantially completely around the 360 degrees periphery of the drum, thus subjecting the material to the maximum hammering action before the material is discharged.

Another object is to provide such a mill that will be lower in height, the resultant lowering of its center of'gravity serving tomake the machine more stable in its mounting and relatively free from objectionable vibration.

Still another object is to improve the reducing action by mounting shredder teeth on the face of the hammer carrying rotor adjacent the feed opening,,so that a. preliminarybreaking up of the material is effected before the material is subjected to the reducing action of the hammers.

These. and other desirable objects may be accomplished by the structure selected for illustration in the accompanyingdrawings, in which form a vertically disposed cylindrical drum is provided. Carried in the drum is a rotor having on its periphery swinging hammers cooperating with a screen on the inside circumferential face of the drum to reduce material fed into the drum through a side opening provided therein for that purpose. The greater circumferential portion of this screen is backed by the periphery of the drum,-

so that reduced material cannot pass through the screen. An arcuate portion of the screen, howscreen into a passage-way arranged at one edge of the drum, said passage preferably being vertically curved to cause the material to move downwardly to an auger at the bottom thereof, which moves the material into a blower or fan housing from which the reduced material is pneuthe drum instead of directly underneath it, and,

as a result, the height of the mill may be substantially lowered. The discharge passage-way men- I tioned is bounded atone side by an arc of the concentric drum screen, while its other side is preferably formed by an extension wall of the circular drum, which wall begins approximately at the top center point of the drum, leaving it along a tangent line, and then with a gradually increasing curvature spacing away from the adjacent arc of the screen to merge in a straight line perpendicular to the floor on which the mill stands. As a result, the passage gradually enlarges from top to bottom to handle an increasing volume of material. At the bottom of the passage, the transverse auger moves the material into the fan housing. Further, the face of the rotor adjacent the feed opening is provided with diametrically aligned bars, 'carrying shredder teeth which serve the purpose of preliminarily breaking up the material as it is fed into the reducing drum.

In the drawings:

'Figure 1 is a side elevational viewof the mill, as viewed from the driving side thereof;

Figure 2 is a side elevational view of the mill, as viewed from the-feeding side;

Figure 3 is a transverse cross sectional view, as seen along the line 3-3 appearing in Figure 5, when viewed in the direction of the arrows;

Figure 4 is a detail, transverse sectional view through the auger and fan device, as seen along the line 4-4 appearing in Figure 5 when looking in the indicated direction;

Figure 5 is ;a face view of the interior of the reducing drum, showing the rotor and other parts, as viewed approximately along the line 5-5 in Figure 3 from the feed side and'showing a portion of the screen in section;

Figure 6 is a face view from the drive side showing the interior of the drum, with the rotor removed to illustrate the relative locationof the -"feed opening with respect to the discharge pas sage-way; and,

' Figure '7 is an elevational view of the bar carrying shredder teeth. a

The mill comprisesbase plates l0 mountedon runner supports H. The plates l0 carry two vertically disposed, spaced apart, sheet metal plates 1'2, which constitute the parallel sides of a cylindrical drum l3, the sides being appropriately connected by a circular piece I 3' to form the cylindrical or circular" drum. An upper, arcuate portion of the drum I3 is hinged at M to provide a cover l5 clamped in place removably by a latch l6, whereby the cover l5 may be 55 drum l3.

One side plate ll of the drum is provided with an elongated opening |1 disposed vertically and off center with respect to the center of said wall l2, which opening constitutes the feeder opening for the entry of the material, that is to be reduced, into the drum. A hopper I8 is carried by a brace IS on said wall l2, the hopper arranged to feed material to the opening H.

The other wall 12 of the mill carries at its center a sleeve 20 in which is journaled a drive shaft 2| carrying a large pulley 22 and a wide pulley 23. The shaft 2| extends centrally into the drum l3 and carries at its end within the drum a rotor 24 in the form of a circular disk, which disk adjacent its periphery and on the face adjacent the feed opening l1 carries at circumferentially spaced points, brackets 25 that support pins 26, on which are hingedly or swingably mounted reducing hammers 21.

Closely fitting the circular part l3 of the drum is a circular screen 28 provided with holes, which foraminous interior surface cooperates with the hammers 21 in reducing the material. The circular wall l3 adjacent the top point of the circle, as seen in Figure 5, projectsout from the circle at a tangent, to form' an extension 29 of the wall, which curves away from the concentric drum l3 on an increasing radius or curvature to a point substantially along the horizontal diameter of the machine, and thence said wall 29 moves down, as at 30, in a vertical line or perpendicular to the floor on which the machine stands. ing curvature of the wall 29 begins substantially at the hinge l4 and moves in a direction away from the latch IE or the cover I 5. The section of the screen 28 adjacent this curved wall 2930 is preferably a separate piece, as indicated at 3|, and it may have holes somewhat'larger than the holes in the screen 28, said screen 3| running from a point adjacent the hinge l4 to a point near the bottom ofthe drum l3, as shown in Figure 5. The arcuate section 3| of the screen 28 is a concentric continuation of the screen 28 and forms a cylinder or circle therewith. This arcuate section 3| is carried in guideways 32 to permit withdrawal of the screen Section 3|, access thereto being had when the cover I5 is raised. See Figure 5 where screen portion 3| has been shown in section.

It will be noted that a passage-way 33 is formed between the arcuate screen section 3| and the wall 29-30, which passage-way gradually in-- creases in size from top to bottom, as the passage-way is substantially vertically disposed around one side edge of the drum. The screen 3| is open to said passage-way 33, by which is meant that the material reduced within the drum, when it passes the screen 3|, is forced glalrough the holes therein into the passage-way It is of greatest importance to note that this exhaust or outlet screen 3| is so located with respect to the feed opening |1 that the material entering the drum through the feed opening |1 must pass or work its way around substantially the entire 360 degrees of curvature of the .drum

before it reaches the screen 3|, or, at least, the

main portion thereof, and, as a result, assurance is given that the material will be tho-roughly reduced and worked upon by the hammers 21 before it gets to said screen 3|. The direction of r tation of the rotor is indicated in the drawings It will be noted. that this increasraised to permit access to the interior of" the by arrows. The bottom of the passage 33 is formed as a trough 34 between the circular wall of the drum and the lower end of the wall 30, there being a shaft 35 disposed transversely in the sides I2 of the drum, upon which shaft is arranged an auger 36 which receives the reduced material and conveys it transversely into a fan housing 31 disposed at and connected to the driving side l2 of the mill. This shaft 35 projects out of the fan housing 31 where it carries a pulley wheel'38, as shown (in Figure 1, and by means of a belt 39 is connected to be. driven from the pulley wheel '22 heretofore described. An idler pulley 40 may be carried in the manner shown in Figure 1, to tension the belt 39.

The shaft 35, wherein the fan housing 31 carries a fan or blower 4|, which exhausts the material delivered by the auger 36 and blows the same pneumatically up through a vertical pipe 42 and out of the machine to any suitable point desired T where the material will be accumulated or caught in bags or other suitable receptacles in any well known manner.

' Just below the feed opening l1 and to one side thereof in the direction of rotation of the rotor 24, the drum I3 is open, as at 43, to communicate with a chute 44 for catching stones and other heavy foreign particles, to trap the same. Such particles, being heavy, are obviously forced outward centrifugally and caught in said trap 44."

The lower end of this trap 44 is provided with a slide or door 45 that may be slid out to remove such foreign objects from the machine. The trap 44 and auger 36 are disposed on opposite sides of the vertical diametric line of the drum l3 and adjacent the lower curvature of said drum.

To make the reducing action of the rotor 24 and its hammers 21 more eflicient, a preliminary reducing action is provided by means of channel, or U-shaped shredder teeth 46 secured by bolts 41 to bars 48, there being two such bars 48 carrying shredder teeth 46 arranged diametrically in alignment across the face of the rotor 24 adja cent the feed opening |1, so that material entering the opening I1 is initially broken up or shredded bythese teeth 46 before the material moves centrifugally out to the circumference of the drum |3 where the action of the hammers 21 and screens 28, 3| finally reduce the material.

. machine permits of a more stable mounting-which will eliminate Vibration and, incidentally, .make feeding of the machine more easy.

A belt from any source of power, such as from an engine or a tractor, will be connected to the wide pulley 23 to drive the machine.

From this description it will now be obvious that the location of the passage-way 33 with respect to the feed opening I1 is such that, with the direction of rotation of the rotor being such that it is, material in being operated'upon by the hammers must be carried around substantially the entire 360 degrees of the periphery of the drum before the material reaches the screen 3| through which it is to pass in reduced form into the passage-way 33. This is highly desirable, as it permits the hammers 21 and shredders 46 to be reduced. Further, it enables such location of operate to a maximum extent on the material to v the passage-way 33 at the edge of the machine to permit lowering of the over-all height of the ma-- Also, the shredders initially reduce the chine. material as it is fed into the machine and, as a result, all of thefeatures-of this invention cooperate in a manner to produce a finer grade of milling. Thus, all of the objects of the invention heretofore recited are accomplished.

It is the intention to cover all such changes and modifications of the form of .invention herein shown as do not depart in material respects from the spirit and scope of the invention, which is covered in the appended claim.

What is claimed as new is:

A hammer mill comprising a drum having two upright spaced sides and a cylindrical portion connected therebetween, a screen lining the inner periphery of said cylindrical portion, an arc of the screen along one side edge of the drum being open for the passage of ground material therethrough into a discharge passageway arranged vertically and adjacent said open arc of the screen and delineated by a wall extending from the drum from a point near the top thereof and along a tangent line and gradually curving downwardly on increasing radii to a point substantially on the projected horizontal diameter of the drum, said wall then continuing substantially vertically downwardly alongside the drum to form a'gradually enlarged passageway from top to bottom, said ground material discharging through said open portion of the screen only, a rotor disk having peripheral hammers rotatable within the drum, one face of the disk carrying reducing cutters thereacross, one upright side of the drum having a feed opening arrangedoif center relative to the axis of the disk and serving to feed material to said adjacent face of the disk, said feed opening being also arranged in proximity to the open arc of the screen and discharge passageway whereby material in process is carried around substantially the entire periphery of the drum before reaching the discharge portionv of the screen, and an auger conveyer at the lower end of the discharge passageway for moving ground material fromthe said passagewayu t ALEXUS C. LINDGREN.

CLEMMA R. RANEY. 

